Brown Dwarfs

Retrieving Young Cloudy L-Dwarfs: A Nearby Planetary-Mass Companion BD+60 1417B and Its Isolated Red Twin W0047

By Keith Cowing
Status Report
July 8, 2024
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Retrieving Young Cloudy L-Dwarfs: A Nearby Planetary-Mass Companion BD+60 1417B and Its Isolated Red Twin W0047
Extracted mid-infrared spectra for BD+60 1417B and W0047 with important molecular gas highlighted. — astro-ph.SR

We present an atmospheric retrieval analysis on a set of young, cloudy, red L-dwarfs — CWISER J124332.12+600126.2 and WISEP J004701.06+680352.1 — using the Brewster retrieval framework. We also present the first elemental abundance measurements of the young K-dwarf (K0) host star, BD+60 1417 using high resolution~(R = 50,000) spectra taken with PEPSI/LBT.

In the complex cloudy L-dwarf regime the emergence of condensate cloud species complicates retrieval analysis when only near-infrared data is available. We find that for both L dwarfs in this work, despite testing three different thermal profile parameterizations we are unable to constrain reliable abundance measurements and thus the C/O ratio.

While we can not conclude what the abundances are, we can conclude that the data strongly favor a cloud model over a cloudless model. We note that the difficulty in retrieval constraints persists regardless of the signal to noise of the data examined (S/N ∼ 10 for CWISER J124332.12+600126.2 and~40 for WISEP J004701.06+680352.1).

The results presented in this work provide valuable lessons about retrieving young, low-surface gravity, cloudy L-dwarfs. This work provides continued evidence of missing information in models and the crucial need for JWST to guide and inform retrieval analysis in this regime.

Caprice L. Phillips, Jacqueline K. Faherty, Ben Burningham, Johanna M. Vos, Eileen Gonzales, Emily J. Griffith, Sherelyn Alejandro Merchan, Emily Calamari, Channon Visscher, Caroline V. Morley, Niall Whiteford, Josefine Gaarn, Ilya Ilyin, Klaus Strassmeier

Comments: Accepted to ApJ
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2407.01694 [astro-ph.SR] (or arXiv:2407.01694v1 [astro-ph.SR] for this version)
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Submission history
From: Caprice Phillips
[v1] Mon, 1 Jul 2024 18:06:11 UTC (14,418 KB)


Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) πŸ––πŸ»